The present invention relates to a method and device which encode main information, such as tone control information (MIDI data), and supplementary or additional information for storage in an electronic storage medium, and reproduce original main and additional information on the basis of the encoded main and additional information stored in the storage medium. The present invention also relates to an electronic storage medium containing such encoded main and additional information, or a software program for implementing the above-mentioned method and device.
In recent years, it has become possible for us to readily create music data, image data, waveform data, etc. and make various alterations to these data by use of a personal computer. Thus, using a personal computer, we can freely read out music data, image data, waveform data, etc. recorded on a commercially available storage medium, such as an FD (Floppy Disk), CD-ROM (Compact Disk-Read Only Memory) and LD (Laser Disk), and make various alterations to the read-out data.
However, because the copyright on the data recorded on a commercially available CD-ROM or LD is owned by the distributor or manufacturer of the storage medium, freely altering the recorded data would constitute an infringement of the copyright and hence should not be tolerated.
At present, in an attempt to obviate such a copyright infringement, copyright indication data specifying who owns the copyright on main data, such as music data, image data or waveform data, recorded in a main data recording section of a CD-ROM or LD is attached as additional information to a header section, separate from the main data recording section, of the storage medium, so as to clearly indicate the copyright holder. Other than such copyright indication data, the additional information sometimes includes information indicative of the title of the music data, image data and waveform data, or recording-format information that indicates a particular sort of data compression technique used for compressing the data.
However, because the data can be freely rewritten or altered by use of a personal computer or otherwise, a significant problem may be encountered that any of the additional information, such as the copyright indication data, is readily deleted, altered or rewritten on purpose or by mistake. In particular, where such additional information is stored in the header section, the additional information may be deleted or altered quite easily.
Further, with the recent advancement of communication networks, there could arise another significant problem that music data, image data or waveform data with the copyright indication data deleted or alerted in an unfair manner is widely distributed via communication networks.